The proposed fines cover four separate instances where the FAA says American was negligent in either maintaining their aircraft or did not follow proper maintenance procedures.

The largest of the proposed fines, for $625,000, involves a computer on an MD-82 that was not replaced when it should have been. The FAA claims the plane with the faulty computer was flown 10 times before the computer was replaced.

In the second case, the FAA announced today that they’re also proposing a $300,000 civil penalty against American for not properly documenting a malfunctioning speed indicator on an MD-82, and for allowing the plane to be flown in conditions in which it should not have been operated.

The FAA says a heater meant to keep an externally mounted speed sensor from freezing over had broken, thus the the plane should only have been flown during daylight hours on clear days until the indicator was repaired. However, the pilots were never made aware of the problem and subsequently flew the jet at night and in poor weather conditions.

The third largest fine being proposed by the FAA is for allegedly not properly recording all the steps in a maintenance check on an MD-82. The $87,500 proposed penalty also claims that maintenance crews replaced a landing gear on the plane without making a note of it in the plane’s logbook.

At $75,000, the smallest of the proposed fines against American claims that the airline did not correctly follow an airworthiness directive regarding the inspection of rudder components on certain Boeing 757s and flew four 757s out of compliance in March 2008.

The airline is, of course, taking this all very seriously. They are reviewing all the fines and will be meeting with the FAA to chat about them.

“Safety is fundamental to the American Airlines culture and to our success,” an airline rep said in a statement. “American is the only U.S. airline that continues to handle the majority of its heavy maintenance with in-house, FAA-certificated mechanics that have met and passed all FAA experience requirements, written tests, and practical examinations.”